Myasthenia Gravis: Frequently Asked Questions

Symptoms/Diagnosis

What is myasthenia gravis and what are common symptoms?

Myasthenia gravis (MG) is an autoimmune neuromuscular disorder that affects voluntary muscles. Common symptoms can include a drooping eyelid, blurred or double vision, slurred speech, difficulty chewing and swallowing, weakness in the arms and legs, chronic muscle fatigue and difficulty breathing. The weakness tends to increase with continued activity and can be improved with periods of rest. Not everyone will display all symptoms, and symptoms can fluctuate.

I think I have MG. What do I do?

We can provide you with general information regarding MG, but you should consult with your doctor if you think you have MG.

How does the doctor test for MG?

A diagnosis can be confirmed in several ways, including the following:

Acetylcholine Receptor Antibody— a blood test for the abnormal antibodies can be performed to see if they are present. Acetylcholine Receptor Antibody testing- Approximately 85% of MG patients have this antibody and, when detected with an elevated concentration the AChR antibody test is strongly indicative of MG.

Anti-MuSK Antibody testing— a blood test for the remaining 15% of MG patients who have tested negative for the acetylcholine antibody. These patients have seronegative (SN) MG. About 40-70% of patients with SNMG test positive for the anti-MuSK antibody. The remaining patients have unidentified antibodies causing their MG.

OfficeTests—Sleep, Ice Pack and Edrophonium tests are examinations performed by specialists to evaluate an improvement in strength that may be consistent with MG.

Electromyography— (EMG) studies can provide support for the diagnosis of MG when characteristic patterns are present. Repetitive Nerve Stimulation is used to check for a pattern of response that is characteristic of MG.

Single Fiber EMG— studies can provide support for the diagnosis of MG when characteristic patterns are present. The single fiber EMG and AChR antibody test are primary tests used to confirm a clinical diagnosis of MG.

Medications/Treatment

How is MG treated?

The goal of MG treatment is to remove antibodies, reduce antibodies, and inhibit the binding of antibodies through the various medications and treatments available. (from Summer 2006 newsletter article by K. Sivakumar, MD)

There is no known cure for MG, but there are effective treatments that allow many people with MG to lead full lives. Common treatments include medications such as Mestinon® (pyridostigmine), prednisone, Cellcept® (mycophenolate mofetil), Imuran® (azathioprine), cyclosporine, and treatments such as thymectomy, plasmapheresis, and intravenous immunoglobulin (IvIg) infusions. Spontaneous improvement and even remission may occur without specific therapy. Rest and a well-balanced diet can help.

Are there medications a patient with MG should not take?

There are certain drugs that patients with MG should avoid or only use with caution. You should always discuss these concerns with your doctor or neurologist; make sure these professionals knows every drug you are taking, including ove-the-counter medications. You pharmacist may be another good resource. For more information on drugs MG patients should avoid or only use with caution you can see the following links: Emergency Alert Card 1, Emergency Alert Card 2, Medications and Myasthenia Gravis.

Why aren’t my medications working?

We can provide you with general information about medications you may be taking and on various treatments that are often used to treat MG, but for specific medical questions, you will need to talk to your neurologist.

Will my MG go away?

In some cases, MG may go into remission for a time, during which no treatment is necessary.

Is it safe to switch to generic Mestinon® (pyridostigmine)?

The generic form of Mestinon® has been on the market since February 2003, and to our knowledge no studies have been conducted as to the relative effectiveness of the medication in relation to the brand version. By law, the generic medications must have the same active ingredients as the brand name medication; however, the “fillers” or excipients may differ.

Can people with MG receive the flu shot?

Medical decisions should always be discussed with your doctor. As the flu shot is not a live vaccine, it is not strictly forbidden for people with MG; however, there may be some instances in which the vaccine is not advised.

Causes

How did I get MG?

Often, the cause of MG contraction is not known for the particular patient. It is possible to contract MG from Penicillamine, which is used to treat Wilson’s disease, rheumatoid arthritis, other chronic autoimmune diseases, and cystinuria. It is also possible to contract MG by being treated with interferon alpha, or through a bone marrow transplant. (From “Medication and Myasthenia Gravis”).

Is MG hereditary?

Researchers are uncertain of the cause of MG, but do not believe that it is hereditary. A genetic predisposition to autoimmune diseases can run in families, but MG is not thought to be directly hereditary.

Is MG contagious?

Researchers are uncertain of the cause of MG, but do not believe that it is contagious.

General Facts

How many people have MG?

Approximately 20 out of 100,000 individuals in the U.S. have been diagnosed with MG. However, MG is considered under-diagnosed and the prevalence is thought to be much higher.

At what age do most patients get MG?

The most common age at onset is the second and third decades in women and the seventh and eighth decades in men. As the population ages, the average age at onset increases correspondingly; now males are more often affected than females, and the onset of symptoms is usually after age 50.

Will my children get MG?

Researchers are uncertain of the cause of MG, but do not believe that it is hereditary or contagious. A genetic predisposition to autoimmune diseases can run in families, but MG is not thought to be directly hereditary. There is a 12% to 20% incidence of neonatal myasthenia in infants born to mothers with MG. Neonatal myasthenia is a temporary condition of general weakness in a baby and usually occurs within the first 24 to 48 hours after birth and may last days or weeks. It is usually self-limited, lasting three to five weeks, but occasionally lasts longer.

Pregnancy

Will I be able to have children?

Myasthenia gravis does not affect the normal growth and development of the fetus. Many women with MG have successful pregnancies. There is a 12% to 20% incidence of neonatal myasthenia in infants born to mothers with MG. Neonatal myasthenia is a temporary condition of general weakness in a baby and usually occurs within the first 24 to 48 hours after birth and may last days or weeks. It is usually self-limited, lasting three to five weeks, but occasionally lasts longer.

Work

Will I be able to continue working?

This partially depends on the nature of your job and your MG, but most MG patients continue working successfully. You may wish to contact the Ticket for Work Program which is a self-sufficiency employment program for people with disabilities who are interested in going to work. 1-866-968-7842 or http://www.yourtickettowork.com/program_info.

Doctors

Can you refer me to a specialist in myasthenia gravis?

MGFA cannot provide referrals for liability reasons. In general, we suggest that people see a neurologist who focuses on neuromuscular conditions at a university medical center. You may also wish to contact your local chapter, as they may have some ideas for you as well.

Literature/Research

Where can I get information to show my doctor?

You or your doctor can request a professional packet for your doctor and we will send a packet via US Mail. Please allow two weeks for delivery.

Where can I get more information on MG?

The Myasthenia Gravis Foundation of America (MGFA) produces and distributes informational pamphlets available to the general public. These materials describe various aspects of the illness, information on treatment programs and a number of other selected topics. You may download and print our materials. If you have difficulty downloading and printing, request a packet and we will send it via US Mail. Please allow two weeks for delivery.

Where can I get the Practical Guide or Survival Guide?

MGFA does not publish the Practical Guide or Survival Guide. If you would like copies of those publications, you can contact the Myasthenia Gravis Foundation of California at 800-574-7884 (if in California or Nevada) or 323-887-0056, or access www.myasthenia-ca.org for more information.

Where can I get more information on research?

A research summary from our annual Scientific Session can be found on our Web site. Information of other research is also available here.

Do you have a newsletter?

Yes. Foundation Focus is a quarterly publication that we distribute at no charge, although we do appreciate donations to help cover our expenses. We can send the newsletter by mail or e-mail. To subscribe, contact the national office.

MGFA newsletters from the past several years can be found on our Web site. Click here >

Chapters/Support Groups

Do you have a chapter in my area?

We have 16 chapters throughout the country. You can check here to see if there is one in your area.

Do you have a support group in my area?

You should contact your area chapter to find out if there is a support group in your area. If there is not a chapter in your area you may wish to contact the North American Chapter here.

Donations

How do I make a donation to MGFA?

If you’d like to donate in memory or in honor of an individual, we generally send an acknowledgement to your designee (with the dollar amount omitted), as well as a thank you note to the person who made the donation. Please include the person’s name and address that you’re honoring and we’ll promptly send the acknowledgement.

Thank you for your support of MGFA.

Financial Assistance/Scholarships/Research Fellowships

Where can I get more information about Social Security Disability?

Information about Social Security Disability is available online at www.ssa.gov/disability or you can call 800-772-1213.

Can MGFA provide me with financial assistance for my medical needs?

Our primary purpose is to provide information and promote awareness about myasthenia gravis, and unfortunately we do not have funds to assist with patient medical needs. You may want to contact your local United Way First Call For Help or another information and referral line in your area to determine whether there are any organizations in your area that offer low-cost medical services or other assistance. You may also wish to see our compiled list of patient assistance resources.

What can you tell me about research fellowships and scholarships?

MGFA does not award scholarships. The Foundation offers research fellowships that are awarded annually. The Post-Doctoral Fellowship is a post-doctoral research fellowship.